Headcanon time: Contrary to popular belief, Sith DO celebrate lifeday. But they give each other really terrible, awfull and insulting gifts to strengthen their hatred.
Plotwist: Sheev actually likes the cream. He will punish Vader for this failure by giving him that "Galaxys greatest husband" mug next year.

This is a fanart, I make no money with this, Star Wars and all of its characters belong, like almost everything, to the allmighty rat.